Thread: Tower Defense on Java

This question probably belongs more in object-oriented programming, but I've grown attached to this thread now.

The way I'm organizing my tower classes is that I have a superclass, called Tower, which contains all the fields that every Tower needs to have. Then, I extend that class to make the actual tower classes. So for example, I have...

public class FlareTower extends Tower

...so that the FlareTower class gains all of Tower's fields and methods.

Where my question comes is here: if I tell a method to take a Tower as an argument, for example...

public void addTower(Tower t)

...or something like that, and then I use the method in a code like this...

addTower(new FlareTower());

...would Java accept that? So, even though I actually input a FlareTower as the argument and the method expects a Tower, wouldn't Java accept it because FlareTower is a subclass based on the class Tower?

Okay. Thank you! That is good to know before I accidentally write 20 more methods than I actually need to.

Alright, now I've got a new little idea. Soon, I will have my OpenGameGUI completed. One of the sections of the OpenGameGUI will be the "Levels" tab. What I want to happen is this: when the user hovers over a level's icon (for example, level 1 will have a square button that says "1" on it), I want a JPanel to appear next to the mouse displaying information on the level (so, if it's locked, say so; if the user has beat it, display his/her best score, etc.).

I know I can use a MouseListener to display the panel tooltips and a MouseMotionListener to move the panel tooltips with the user's mouse, but how can I make the panels that will act as tooltips appear on top of the other Components of the GUI? I've heard of GlassPanes and Z-alignment, but I'd like some advice about which way is the best to go, and may some good documentation to look at. Thanks!

Hmm... A random curiosity struck me. Is there any way to create a gradient fill for components, instead of just using...

<Component>.setBackground(Color c);

...? Or perhaps a special type of color that is actually a gradient? Any help would be appreciated!

Originally Posted by snowguy13

Hmm... A random curiosity struck me. Is there any way to create a gradient fill for components, instead of just using...

<Component>.setBackground(Color c);

...? Or perhaps a special type of color that is actually a gradient? Any help would be appreciated!

You'll want something more like:

LinearGradientPaint gradient = new LinearGradientPaint(start, end, fractions, colors);	
g2d.setPaint(gradient);		
g2d.fillRect(0, 0, getWidth(), getHeight());

You might consider posting separate questions in separate threads.

You might consider posting separate questions in separate threads.

Okay. I'll do that in the future, after this is solved (pointless to start a new thread halfway through a solution).

g2d.setPaint() is telling the g2d (Graphics2D Class, right? or is g2d an instance?) to use the specified gradient to paint Components, and g2d.fillRect() fills the specified area of a... JFrame? Component? How can I apply this to a JLabel?

Thanks for your help!

Yeah, g2d is an instance of Graphics2D. You can get one by overriding paintComponent and casting the Graphics Object, which is actually a Graphics2D Object. And it fills whatever you want, you just have to override paintComponent.